Ab initio is Latin for “from the beginning” or “first premise.” As a result, quantum physics is known as an ab initio model since it investigates the atomic and electronic interactions of particles, beginning with the Schrodinger wave equation (Hamiltonian). As a result, quantum physics investigates a system’s microscopic properties before describing the system’s bulk properties.
Classical mechanics, on the other hand, as an ab initio model, uses Newtonian mechanics to describe intriguing features of a system without taking into consideration the electronic properties. As an ab initio model, classical electromagnetism is governed by the four Maxwell equations, which are the Gauss’ laws of electrostatics and magnetostatics, Faraday’s law, and Ampere’s law. These four equations serve as the foundation for all electrodynamic properties.